The Ruhr area, one of Europe’s largest metropolitan regions, provides attractive career opportunities for outstanding scientists and scholars from around the world. In 2021, Ruhr University Bochum, TU Dortmund University, and the University of Duisburg-Essen established the Research Alliance Ruhr to consolidate their pioneering international research on humanity's most pressing challenges. This alliance encompasses four research centers and a college, marking a new chapter in our enduring collaboration as the University Alliance Ruhr (UA Ruhr), a vibrant community of 14,000 researchers and 120,000 students located in the heart of Germany. Join us and contribute to cutting-edge research at RC Trust, where innovation meets real-world impact. As part of the Research Alliance Ruhr, the Research Center for Trustworthy Data Science and Security unites the expertise of its member universities to bridge the gaps between Psychology & Social Sciences, Artificial Intelligence & Machine Learning, Data Science & Statistical Learning, and Cybersecurity & Privacy. We are seeking to fill a PhD position focused on Human-Centric LLMs as soon as possible. This is a full-time position, with compensation according to the public service agreement: TV-L E12/13.